Pre-eclampsia Flashcards
What are the renal signs of PET?
proteinuria (>0.3g/24hr or ACR >=30mg/mmol (or >=0.3mg/mg)), or random dipstick >=2+, or plasma Cr >=97.2micromol/L, or plasma Cr doubling in absence of other renal disease, or oliguria (<500mL/24hrs)
What are the haematological signs of PET?
thrombocytopenia (plt <150 x10^9/L), haemolysis (schistocytes or red cell fragments on blood film, raised bilirubin, raised LDH, decreased haptoglobin), DIC
What are the hepatic signs of PET?
new onset raised transaminases (>2x ULN) with or without epigastric or RUQ pain
What are the neurological signs of PET?
headache
persistent visual disturbance (scotomata, cortical blindness, photopsia, retinal vasospasm)
convulsions (eclampsia)
stroke
hyperreflexia w sustained clonus
What are the pulmonary, cardiac & utero-placental signs of PET?
pulm oedema
generalised oedema (incl facial & airway)
IUGR
suspected foetal compromise
abnormal umbi artery doppler waveform analysis
stillbirth
What is mild-moderate HTN in pregnancy?
And severe?
2 bps, measured @ least 4hrs apart, SBP >=140mmHg (but <160mmHg) +/- DBP >=90mmHg (but <110mmHg)
Severe is SBP >=160mmHg +/- DBP >=110mmHg (confirmation within mins= sufficient for Dx of severe)
Any SBP >170mmHg= a medical emergency requiring Rx
What’s gestational HTN?
New-onset HTN arising after 20/40 gestation without features of PET, resolves within 3/12 postnatal
What’s chronic HTN in pregnancy?
HTN (SBP >=140mmHg OR DBP >=90mmHg) confirmed prior to conception or prior to 20/40, including pts w well-managed HTN entering pregnancy
What’s pre-eclampsia? And what are the signs of “significant end organ dysfunction” they refer to?
A multi-system disorder, new-onset HTN (SBP>=140mmHg OR DBP >=90mmHg, on 2 occasions, 4 hrs apart in previously normotensive women- if a SBP is >=160mmHg or DBP >=110mmHg, can confirm within mins) with proteinuria (>=30mg/mmol) OR significant end-organ dysfunction with-or-without proteinuria, after 20/40 gestation, in a previously normotensive woman, resolves within 3/12 postpartum
significant end organ dysfunction=g
proteinuria (>=0.3g/24hrs or ACR >=0.3mg/mg or dipstick >=2+)
plt <100 x 10^9/L
LFTs 2x ULN
Cr >97.2micromol/L or doubling in absence of other renal disease
Pulmonary oedema
New-onset persistent severe headache or visual symptoms
What is the Rx goal with acute antihypertensive management for severe PET?
SBP 130-150mmHg/80-90mmHg (avoid maternal hypoT)
What dose of labetalol could be used for acute anti-hypertensive Rx? onset & DOA?
20mg slow IV over 2mins, can repeat 40-80mg every 10mins to max 300mg as required
Onset is 5-10mins, DOA 4hrs but Cl is prolonged in hepatic dysfunction
What is labetalol?
nonselective B1 & B2 & selective alpha1 blocker (more potent B than alpha, lowers SVR but reflex tachycardia is attenuated by B block, still have pre-syn alpha 2 so -ve feedback catecholamine release can occur)
Risks w labetalol?
crosses placenta so ?risk foetal brady, hypoT & hyperglycaemia, also it transfers into breastmilk
can get headache, nausea, scalp tingling, orthostatic hypoT (but B block limits the tachycardia), risks brady.
Contraindicated in asthma, chronic airway limitation (bronchospasm)
What pregnancy category are the antihypertensive drugs used for maternal HTN?
all C: drugs which, owing to their pharmacological effects, have caused or may be suspected of causing, harmful effects on the foetus or neonate without causing malformations
What are contraindications to hydralazine? Adverse effects? Max dose?
Direct-acting smooth muscle relaxant, mainly in resistance arterioles, by inhibiting Ca++ release from SR of arterial smooth muscle cells. The reflex tachycardia from VD will incr HR & contractility so avoid if HR >125bpm, myocardial insufficiency, RV heart failure, care if CAD, CVD, hepatic or renal impairment. May cause tachy, flushing, headache, palpitations & with long-term use, oedema & SLE. Max dose 30mg over 24hrs.
Doses of hydralazine?
5-10mg over 3-10mins (lower end dose range if foetal compromise), repeat 5mg IV every 20mins as required, onset 5-20mins, half life 3hrs or 45mins in rapid acetylators. max 30mg/24hrs. Consider infusion (starting at 10mg/hr, titrate) if use 20mg, reduce/cease if HR 125bpm.
What’s an oral option for acute management severe HTN in pregnancy? Adverse effects?
Nifedipine- 10-20mg IR tablet, onset is 30-45mins, repeat after 45 mins to a max 80mg/day. Also causes myometrial relaxation (DHP CCB). May cause VD, flushing, headaches, hypoT, reflex tachycardia, AV block or other conduction defects
What are the rules of thumb with fluids in PET?
large vols (b4 or after birth) risk pulm oedema & worsening peripheral oedema so only consider prior to regional (nil for epidural, <500mL for spinal) or hydralazine or immediate delivery or if oliguric & we suspect volume deficit (postpartum, <80mL UO/4hrs is physiological so don’t require IVT unless serum plasma Cr is rising).
For severe PET:
-in labour: restrict fluid intake to 60-80mL/hr & monitor hourly FBC (*including Mg++ & oxytocin infusions!)
-post-birth: restrict IV crystalloid to 1.5L in the first 24hrs if no other complications, strict FBC
What other obstetric emergency are PET, eclampsia & HELLP a risk for?
Primary PPH- consider carbetocin for these pts
What proportion of PET occurs postpartum?
40%, de novo postpartum PET most common days 3-6 & in PET, peak postpartum BP is often on days 3-6 (also lever enzymes & thrombocytopenia will often worsen in the first few days after birth before they improve)
In which group of patients with PET are NSAIDs not recommended?
Those with severe PET &/or renal impairment (esp if volume depleted)
Should also avoid NSAIDs if significant blood loss, thrombocytopenia or additional risk factors for bleeding
What is HELLP?
Indicates severe disease in pre-eclampsia.
-Haemolysis (rare)- microangiopathic haemolytic anaemia with schistocytes/rbc fragments on blood film, other signs haemolytic (elevated LDH, indirect bilirubin, haptoglobin)
-Elevated liver enzymes- transaminases >2x ULN, may have profound clotting defect (check INR)
-Low platelets- <=100 x 10^9/L (common)- consider platelet transfusion if low platelets considered a hazard to operative birth or if significant PN bleeding is attributed to pre-eclamptic thrombocytopenia. Platelet nadir 24-48hrs after delivery.
May be sudden onset, first sign may be seizure, be wary of RUQ pain in pregnant women
85% of women with HELLP have diagnostic criteria for preeclampsia (ie. in 15% there’s no HTN or proteinuria)- thought same pathophysiology as PET (systemic endothelial dysfunction, inadequate placentation)
